


Fire and Brimstone and Gnashing of Teeth

by ImWithEnjolras



Category: Haikyuu!!
Genre: A LOTTA DICK, Basically, Demon AU, M/M, PWP, probably
Language: English
Status: Completed
Published: 2016-07-18
Updated: 2016-07-18
Packaged: 2018-07-24 17:19:57
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,206
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7516693
Author URL: https://archiveofourown.org/users/ImWithEnjolras/pseuds/ImWithEnjolras
Summary: <blockquote class="userstuff">
              <p>In hindsight, Ryuu was definitely not to blame. He’s always been a tactile kind of boyfriend. Not that Koushi minds - in fact, he doesn’t mind at all; he loves it! It’s just that...now, Ryuu’s penchant for running his hands along Koushi’s skin and tracing absentminded patterns between the freckles he finds there has gotten them into a spot of trouble. It’s caused a bit of a stir in Koushi…</p><p>...a reaction, if you will.</p>
            </blockquote>





	Fire and Brimstone and Gnashing of Teeth

**Author's Note:**

> This is a fill for Doxy's prompt for SASO2016
> 
> https://sportsanime.dreamwidth.org/15224.html?thread=6910584#cmt6910584

In hindsight, Ryuu was definitely not to blame. He’s always been a tactile kind of boyfriend. Not that Koushi minds - in fact, he doesn’t mind at all; he loves it! It’s just that...now, Ryuu’s penchant for running his hands along Koushi’s skin and tracing absentminded patterns between the freckles he finds there has gotten them into a spot of trouble. It’s caused a bit of a stir in Koushi…

...a reaction, if you will.

“What in  _ the fuck, _ Sugawara Koushi?!”

Okay, so not exactly the thing anyone wants to hear from their boyfriend, but give Koushi a bit of a break.

“You shouldn’t have started drawing weird shit on my skin, Ryuu!” He reprimands, extremely exasperated. It’s probably two in the morning and this isn’t exactly how he had envisioned spending it. Koushi glances at their rug, forlornly grieving its loss to purple demonfire and his stupid summoning circle. “I loved that rug.”

Oh yeah. There’s still some explaining to do. Oops.

“How was I supposed to know?!” Ryuu stares in wide-eyed wonder. Right in front of his eyes, the love of his life, was transforming. Not metaphorically and not in any magical-girl-soldier way. Koushi’s skin fucking  _ glows _ as gold symbols and swirls flow across the surface. Instead of the warm brown he’s used to, eyes as gold as the new markings on Koushi’s skin blink back at Ryuu. “Holy...shit…”

Ryuu can’t tear his gaze away from Koushi. 

Not that that’s unusual, but this is a slightly different version of Sugawara Koushi.

“Don’t-- don’t look at me!” Koushi shouts out in desperation, arms crossing in front of his face to hide his form from Ryuu.

Ryuu’s gut drops at the fear in Koushi’s voice. He immediately lurches forward, gently grasping Koushi’s hands. He tries to pull Koushi’s arms away from his face, but his stomach twists at Koushi’s barely concealed whimper.

“Babe, please. Please, look at me.” Ryuu begs and after a few moments, he feels Koushi’s muscles relax. He gasps at Koushi’s newly transformed facial features, but he holds Koushi’s hands tight within his own so he doesn’t hide away again.

“I’m sorry. I’m so sorry--” Koushi cries, tears flowing from his golden eyes. “I should’ve told you or something that I’m this demon thing! I’m-- I’m just so sorry. I’m a fre--”

“No.” Ryuu says firmly. Koushi’s gaze darts up to Ryuu’s in surprise and Ryuu’s gut clenches again when he realizes that this is the first time Koushi’s looked him in the eye since this all began. “You’re beautiful.”

Ryuu knee-walks forward, positioning himself so that Koushi kneels between Ryuu’s thighs. Koushi is holding his breath, watching as Ryuu gazes at him intently, slowly rubbing circles into the palms of his hands. “Ryuu what are you--”

“Koushi, you’re so beautiful. I don’t know how many times I’ve gotta say it, but..” Ryuu lets go of one hand, gently reaching up to trace Koushi’s cheekbone with his thumb, golden swirls concentrating before dispersing underneath his fingertips. The silence between them lengthens as Ryuu continues touching Koushi. In response, Koushi leans into Ryuu’s palm. “My god, you’re so beautiful, sometimes I don’t know what to do with myself. Just..just the thought of you nearly makes me lose my goddamn mind.”

Koushi inhales shakily as Ryuu brings his hand to the back of his neck. “R-Ryuu..”

Ryuu carefully leans forward, nudging Koushi’s nose with his own. “The things you do to me, Koushi...the things I want to do to you..”

At this, Koushi gasps audibly. His hands snap forwards, one holding onto Ryuu’s upper arm and the other grasping Ryuu’s waist needily. Koushi brings himself closer to Ryuu, smoothly straddling one of Ryuu’s thighs. With a groan, Ryuu pulls Koushi into a kiss, swallowing a particularly loud moan from Koushi.

The golden symbols on Koushi’s skin glow brighter with every desperate inhale. When Ryuu pulls back, Koushi is so beautiful in his breathlessness, chasing after Ryuu’s lips. Ryuu feels like his heart is beating right out of his chest. Koushi blinks up at him, hands having found their way to the nape of Ryuu’s neck, rubbing along the prickly hairs there. 

“Ryuu..” Koushi whispers, still a little breathless. “I love you.”

Ryuu immediately tugs Koushi back towards his chest, fingers sliding underneath the waistband of Koushi’s boxers. When he pulls back again, he’s slipped Koushi’s boxers down his thighs and Koushi helps by kicking them off completely. Ryuu pauses eyeing Koushi’s pink boxers decorated with little stars, moving only to bring Koushi tight against his body. 

“Cute,” Ryuu chuckles, to which Koushi slaps Ryuu’s shoulder. 

“Hey, don’t laugh! I’m an all powerful demon!” Koushi’s declaration ended with his giggles. A quick flick of his wrist disappeared Ryuu’s own boxers.

All powerful demon indeed.

“Well…” Ryuu whispers, eyebrows raised and not bothering to hide how impressed he is. “That certainly makes things a lot easier!” 

Koushi bursts out laughing, leaning further against Ryuu. Eventually their laughter dies down and Ryuu resumes gazing at Koushi, sending tendrils of fire and gold gliding on his skin. Ryuu ghosts his fingertips up along Koushi’s arms, tracing up his elegant neck, just grazing his jaw. Ryuu continues following the natural lines of Koushi’s face, eventually meeting the point just above Koushi’s temples where his golden horns protrude.

Koushi’s breath hitches, but Ryuu doesn’t move away from him. His horns aren’t particularly sensitive, but that fully depends on who he deems worthy enough to touch him. And Ryuu is not only unafraid of him, but it would take some extraordinary circumstances for anyone to not see just how much Ryuu loves Koushi. He doesn’t recoil from Koushi and the demon thinks that his heart just might explode out of how much he loves this man. 

Ryuu kisses Koushi again and hisses at the sensitive-heat growing between them. Ryuu tips back, Koushi fitting comfortably in his lap. He grinds down against Ryuu’s abs, exhaling shakily against his lips. 

“Mine…” Koushi whispers, kissing a corner of Ryuu’s mouth. “...I’ll take you…”

Ryuu smirks. “Where?”

“Down with me.” Koushi gazes at Ryuu with half-lidded eyes.

“With hellfire and brimstone?”

Koushi smiles, before playfully biting the air in front of Ryuu’s nose. “And gnashing of teeth.”

Ryuu brings Koushi’s lips down to his, sharing open-mouthed and wet kisses. He blindly searches for the bottle of lube with his free hand, easily lubing up his other hand. He traces Koushi’s opening with the middle finger of his left hand. “I’ll always be yours.” Koushi shudders against him, backing into Ryuu’s finger so it sinks into him.

“G-Good.” Koushi throws his arms across Ryuu’s shoulders, groaning as Ryuu fucks him with one finger. “I’m too selfish to share.”

Ryuu growls, thrusting faster into Koushi. Koushi, while waiting for Ryuu to pop the lube open again and spread it over his cock and Koushi’s opening, keeps busy making marks along Ryuu’s neck.

“I’m adding another.” Koushi sighs against Ryuu’s neck as he slides another lubed finger inside Koushi. 

“Ahhhh f-fuck..” Ryuu grins, peppering kisses along Koushi’s collarbone. “S-So good..please...I n-need more..”

Ryuu pauses in his movements, before deftly curling his fingers to just graze along that sensitive bundle of nerves that has Koushi squirming in his lap. “Okay.”

The feeling of Ryuu’s fingers leaving him makes Koushi whine against Ryuu’s ear, but he is quickly placated by the shiver-inducing pressure of Ryuu’s cock pressing against Koushi’s entrance. All Koushi wants to do is hurry this process up, get split open over Ryuu’s dick and get fucked so hard and so good his moans penetrate through the silencing wards set up through the room. Ryuu, on the other hand, has plans that do not involve speed very much. Instead, he takes his time, guiding Koushi though a slow descent with a firm grip on Koushi’s hips.

Koushi’s left panting, begging so deliciously for Ryuu’s dick that he nearly gives in. But he’s learned every single pleasure point of Koushi’s body, knows exactly how to get Koushi so lost in bliss that even Ryuu’s own vision whites out. 

“Baby. Baby, please. Stop teasing!” Koushi whispers out, breathlessly. But Ryuu only lowers him down one inch. “Please. Pleeease. Stop teasing, stop teasing!” His grip is bruising in Koushi’s hip, but still...only one inch. 

Finally, after what feels like an eternity for both of them, Koushi’s ass meets Ryuu’s thighs. “Holy shit.” Koushi murmurs. “Holy shit, holy shit, holy shit!”

Koushi shudders above him, the heat around his cock is so  _ fucking hot _ . His lover’s whole body shivers, even his insides squeeze Ryuu’s dick at irregular intervals. Ryuu grabs both cheeks of Koushi’s ass, giving them a firm squeeze. Koushi throws his head back, exhaling heavily into the sex-muggy air of their bedroom. He flexes his thighs, testing preemptively exactly how he’s going to fuck himself with Ryuu’s dick.

“Yes.” Ryuu hisses, leaning forward  to take a deep breath against the crook of Koushi’s neck. “Just like that. Take what you need. Take all of it.”

Koushi groans, pushing himself up with his thighs. Ryuu gives a swift, precise slap against Koushi’s ass. “Aah! F-Fuck!”

Ryuu grins. “That’s right, baby. Yeah. Ride my cock. Yeah.” He licks one long stripe along Koushi’s collarbone. “Love how that feels. Shit. Y-Yeah. Fill you up so good. Mmm. That’s it.”

Koushi keeps riding Ryuu, the other doing nothing but enjoying the ride. It’s fast and loud and sweaty as Koushi uses gravity to drop hard back down onto Ryuu’s thighs. Each slap of skin reverberates around the room, a delicious moan from Ryuu following just a moment later. 

Eventually, Koushi’s thigh muscles just can’t keep up, so he resorts to grinding heavily. He circles his hips, each inch of Ryuu’s thick cock hitting different parts inside of Koushi with each pass. Koushi’s fingernails dig into Ryuu’s shoulders, puncturing skin. Ryuu watches all of this with rapture, gaze drinking in every other-worldly beautiful inch of Sugawara Koushi. The gold of his skin glows even brighter, but Ryuu doesn’t miss Koushi just about to put one hand on his cock.

“Oh no, Koushi.” Ryuu whispers, quickly tangling the fingers of both their hands together. “No touching.”

“Fuck you, Ryuu.” Koushi lurches forward, biting Ryuu’s shoulder in retaliation. His hands squeeze Ryuu’s as he frantically starts fucking himself on Ryuu’s cock again.

Ryuu hums. “I think you can come just like this, don’t you think?”

Koushi’s eyes prickle with tears, but he doesn’t stop moving. He can’t. “Oh god. I can’t-- Ryuu please. Please touch me. I can’t--”

“I know you can, babe.” Ryuu tilts his head, quickly catching Koushi’s bottom lip between his lips. “I know you can. You’re so good for me, right? I’m so close too. It’ll be so good if you do it. Do it for both of us.”

A sob rips out of Koushi’s throat as he pulls his hands from Ryuu’s grip just to throw them across his lover’s shoulders. Koushi’s reduced to gasps, moans, and sobs as he fucks himself into oblivion with Ryuu’s cock. Ryuu’s no better off, fingers digging hard into Koushi’s hips, making sure to grind himself into Koushi’s prostate.

“A-A-A-Aaah--” 

“O-Ohh fuck!” Koushi grinds into Ryuu’s lap, collapsing against Ryuu as the cock inside of him hits his prostate so hard his vision goes white. Koushi comes with a silent scream as Ryuu loses himself in his lover’s heat. Koushi feels like he came multiple times, gasps and sobs wracking his body as Ryuu thrusts a few times into his ass.

“H-Haaaahh..” Koushi takes a few more heaving breaths, as Ryuu grinds one last time into him, completely spent.

“I don’t suppose you have clean up powers..” Koushi can’t even find it in himself to answer verbally, so he shakes his head. Not in this state, at least. Ryuu smiles, gently laying Koushi down onto their bed, legs feeling like jelly as he goes to their bathroom to get a damp facecloth. 

Ryuu’s lips quirk up, finding Koushi completely passed out in full demon-form looking completely sated (and well-fucked, Ryuu thinks proudly). He gingerly wipes Koushi off, doing his best to clean his cum from Koushi’s ass. He eventually blindly tosses the facecloth behind him, flopping beside Koushi and gathering his boyfriend into his arms.

Koushi slumbers quietly and Ryuu can’t help the smile that spreads across his lips. His eyes trail up Koushi’s smooth skin, pale in the moonlight, glowing silver and gold. The markings on his skin curl and unfurl slowly and smoothly over Koushi’s skin. Ryuu’s (newly discovered) demon-boyfriend’s chest raises and lowers calmly, completely at peace within Ryuu’s embrace. Ryuu resumes his gentle play with Koushi’s hair, fingers occasionally catching on the bottom of his boyfriend’s horns.

Ryuu feels giddy. He’s purely giddy at the sight of Koushi and all the new secret, beautiful parts of Koushi that he is now privy to. He’s ecstatic that Koushi shared this with him and no longer has to hide his true form from Ryuu.

Ryuu’s so ecstatic, in fact, that the bright, white wings he’s so carefully concealed all his life on his back flash into visibility.

Boy...has Ryuu got a story to tell Koushi in the morning...

**Author's Note:**

> I uh...hope you liked it...me publishing this on Sunday is 100% not sacrilegious at all whatsoever.


End file.
